Prevalence and Molecular Study of G6PD Deficiency in the Dai and Jingpo Ethnic Groups in the Dehong Prefecture of the Yunnan Province.

OBJECTIVES: To estimate the prevalence and mutation types of G6PD deficiency and evaluate the relationship between G6PD genotypes and erythrocyte phenotypes in the Dai and Jingpo ethnic groups in the Dehong prefecture of the Yunnan province, China. METHODS: G6PD deficiency was screened in Dai (1,530 individuals) and Jingpo (372 individuals) populations using a modified G6PD/6PGD ratio assay. Red blood cell traits were analyzed using the Sysmex XE2100 fully automated blood analyzer. PCR-direct sequencing for G6PD genotyping analysis was performed, and then the linkage disequilibrium blocks of the target SNPs were constructed with Haploview 4.2 software. RESULTS: The prevalence of G6PD deficiency was higher in the Dai ethnic group (8.63%) than in the Jingpo ethnic group (5.91%). The major mutations in descending order were rs137852314 G>A, rs72554664 G>A, rs72554665 G>T, and rs137852341 G>T. Hemoglobin concentration was significantly lower in the rs137852314 G>A group than in the normal group (p = 0.021). Mean corpuscular volume and mean corpuscular hemoglobin were substantially higher in the rs137852341 G>T group compared to the normal group (p = 0.049, p = 0.042). A linkage disequilibrium block of 13 SNPs was constructed for the G6PD deficiency group from the Dai sample. CONCLUSIONS: The Dai and Jingpo ethnic groups have distinctive incidence rates and gene frequencies of G6PD deficiency, and the genotypes of G6PD deficiency are associated with erythrocyte phenotypes.

The effect and mechanism of inhibiting glucose-6-phosphate dehydrogenase activity on the proliferation of Plasmodium falciparum.

We screened >40,000 patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency and found that the G6PD Kaiping allele was under the most positive selection for fighting against malaria in the Chinese population. However, the mechanism is unknown. The current study was designed to investigate the anti-malarial effect and mechanism of G6PD deficiency. Dehydroepiandrosterone (DHEA) was utilised for inhibiting the G6PD activity of erythrocytes. Giemsa staining of blood smears and quantitative real-time PCR were used for the detection and quantification of Plasmodium falciparum infection. A transmission electron microscope was used to observe the structural changes of P. falciparum. An atomic force microscopy was used for the analyses of morphology, roughness and Young's Modulus of the infective erythrocyte membrane. When G6PD activity was inhibited by DHEA, the infection rate of P. falciparum decreased, its cell nucleus shrank, the cell organelles and metabolites were reduced gradually and the Young's Modulus of the erythrocyte membrane increased with increasing DHEA concentrations. These data indicated that Plasmodium multiplication would be inhibited in G6PD deficient erythrocytes because the Plasmodium organelles could not obtain enough nutrients, including ribose-5-phosphate and the reducing equivalent, NADPH. Moreover, the Young's Modulus of the erythrocyte membrane increased, which resulted in an increased membrane stiffness and decreased deformation. It was difficult for the merozoites to invade erythrocytes through endocytosis. Understanding these points will have a major effect on searching for new anti-malarial drug targets.

Effects of G6PD activity inhibition on the viability, ROS generation and mechanical properties of cervical cancer cells.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been revealed to be involved in the efficacy to anti-cancer therapy but the mechanism remains unclear. We aimed to investigate the anti-cancer mechanism of G6PD deficiency. In our study, dehydroepiandrosterone (DHEA) and shRNA technology were used for inhibiting the activity of G6PD of cervical cancer cells. Peak Force QNM Atomic Force Microscopy was used to assess the changes of topography and biomechanical properties of cells and detect the effects on living cells in a natural aqueous environment. Flow cytometry was used to detect the apoptosis and reactive oxygen species (ROS) generation. Scanning electron microscopy was used to observe cell morphology. Moreover, a laser scanning confocal microscope was used to observe the alterations in cytoskeleton to explore the involved mechanism. When G6PD was inhibited by DHEA or RNA interference, the abnormal Young's modulus and increased roughness of cell membrane were observed in HeLa cells, as well as the idioblasts. Simultaneously, G6PD deficiency resulted in decreased HeLa cells migration and proliferation ability but increased ROS generation inducing apoptosis. What's more, the inhibition of G6PD activity caused the disorganization of microfilaments and microtubules of cytoskeletons and cell shrinkage. Our results indicated the anti-cervix cancer mechanism of G6PD deficiency may be involved with the decreased cancer cells migration and proliferation ability as a result of abnormal reorganization of cell cytoskeleton and abnormal biomechanical properties caused by the increased ROS. Suppression of G6PD may be a promising strategy in developing novel therapeutic methods for cervical cancer.

A comprehensive analysis of membrane and morphology of erythrocytes from patients with glucose-6-phosphate dehydrogenase deficiency.

Acute hemolytic anemia could be triggered by oxidative stress in the patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. However, the underlying hemolytic mechanism is unknown. To make clear the hemolytic mechanisms, a systematic study on membrane ultrastructure had been undertaken. A comprehensive method was used including atomic force microscopy, scanning electron microscopy, flow cytometer and fluorescence microscopy to analyze the membrane ultrastructure, externalized phosphatidylserine (PS), intracellular Ca(2+) concentration, morphology and the distributions of band 3 protein in G6PD deficient red blood cells (RBCs) after tert-butyl-hydroperoxide (t-BHP) oxidation. The results showed that erythrocyte shrinkage, annexin-V binding to externalized PS on the membrane of early-stage apoptotic cells, the increased membrane roughness and intracellular Ca(2+) concentration, as well as the change of distributions of band 3 protein in RBCs. Compared with the control RBCs, as the concentration of t-BHP up to 0.1mM, the membrane roughness of G6PD deficient RBCs showed significant difference (p<0.05) and as the concentration of t-BHP up to 0.3mM, externalized PS showed significant difference (p<0.05). Furthermore, the population types of RBCs showed dramatic difference between control groups and G6PD deficient groups. Oxidative stress induced more serious erythrocyte apoptosis and resulted in increased roughness of erythrocyte membrane and abnormal distributed band 3 protein in G6PD deficient RBCs. Echinocytes are the predominant abnormal erythrocyte shape occurring in the peripheral blood from patients with G6PD deficiency, which may shorten the RBCs lifespan. The results in the present study will give an increased understanding for the hemolytic mechanism of G6PD deficiency.

Occurrence, Distribution, and Accumulation of Pesticides in Exterior Residential Areas.

Pesticides are commonly applied around residential homes, but their occurrence on exterior surfaces (e.g., pavement) has not been thoroughly evaluated. We collected 360 dust samples from curbside gutters, sidewalks, and street surfaces at 40 houses in southern California to evaluate pesticide occurrence on urban paved surfaces as well as their spatial and temporal distributions. Pesticides and select degradates were ubiquitously detected in dust, with the median concentration of total target analytes at 85 µg kg-1. A total of 75% of samples contained at least five pesticides. As a result of recurring pesticide applications, concentrations increased throughout the summer. The pyrethroids bifenthrin and permethrin accounted for 55% of total pesticides detected in the dust. The highest concentrations in dust were found on the sidewalk and in the gutter. Relative to indoor environments, human exposure risk to pesticides on paved surfaces was estimated to be lower, with the highest potential oral and dermal exposure predicted to be 38 ng day-1 for permethrin. The ubiquitous detection of pesticides on residential outdoor surfaces and the fact that the exterior concentrations did not correlate to the indoor areas highlight the necessity to measure pesticides in both indoor and outdoor areas for complete residential pesticide risk assessment.

Molecular Epidemiological Survey of Glucose-6-Phosphate Dehydrogenase Deficiency and Thalassemia in Uygur and Kazak Ethnic Groups in Xinjiang, Northwest China.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency and thalassemia occur frequently in tropical and subtropical regions, while the prevalence of relationship between the two diseases in Xinjiang has not been reported. We aimed to determine the prevalence of these diseases and clarify the relationship between genotypes and phenotypes of the two diseases in the Uygur and Kazak ethnic groups in Xinjiang. We measured G6PD activity by G6PD:6PGD (glucose acid-6-phosphate dehydrogenase) ratio, identified the gene variants of G6PD and α- and ß-globin genes by polymerase chain reaction (PCR)-DNA sequencing and gap-PCR and compared these variants in different ethnic groups in Xinjiang with those adjacent to it. Of the 149 subjects with molecular analysis of G6PD deficiency conducted, a higher prevalence of the combined mutations c.1311C > T/IVSXI + 93T > C and IVSXI + 93T > C, both with normal enzymatic activities, were observed in the Uygur and Kazak subjects. A case of rare mutation HBB: c.135delC [codon 44 (-C) in the heterozygous state], a heterozygous case of HBB: c.68A > G [Hb G-Taipei or ß22(B4)Glu→Gly] and several common single nucleotide polymorphisms (SNPs) were found on the ß-globin gene. In conclusion, G6PD deficiency with pathogenic mutations and three common α-thalassemia (α-thal) [- -(SEA), -α(3.7) (rightward), -α(4.2) (leftward)] deletions and point mutations of the α-globin gene were not detected in the present study. The average incidence of ß-thalassemia (ß-thal) in Uygurs was 1.45% (2/138) in Xinjiang. The polymorphisms of G6PD and ß-globin genes might be useful genetic markers to trace the origin and migration of the Uygur and Kazak in Xinjiang.

[Chromosomal microarray analysis for lateral ventriculomegaly in fetus].

OBJECTIVE: To investigate the relationship between fetal lateral ventriculomegaly and chromosomal microarray analysis (CMA) abnormalities. METHODS: Fifty fetuses with lateral ventriculomegaly detected by ultrasound and a normal karyotype were included. Forty four fetuses were classified as mild ventriculomegaly (MVM), in which the lateral ventricular atrium was 10-15 mm. Six had severe ventriculomegaly (SVM), with the lateral ventricularatrium being ≥ 15 mm. The fetuses were also divided into isolated (n= 21) and non-isolated groups (n= 29) based on whether they are associated with other anomalies. RESULTS: Thirteen (26%) of the fetuses were found to be abnormal by CMA. For the 44 cases with MVM, 9 (20.9% ) were found to be abnormal, while for the 6 cases with SMV, 4 (66.7%) were found to be abnormal (P>0.05). CMA abnormalities were found in 2 (9.5%) of the 21 fetuses with isolated ventriculomegaly group and 11 (37.9%) of the 29 fetuses with non-isolated ventriculomegaly group (P<0.05). CONCLUSION: Chromosome microdeletions and microduplications are the most common abnormalities found in fetal lateral ventriculomegaly. When ventriculomegaly is associated with other anomalies, the incidence of CMA abnormally is much higher. Prenatal diagnosis is necessary for fetuses with lateral ventriculomegaly.

The Hb H disease genotypes in Southern China.

Abstract We report the genetic data of 435 patients with Hb H (ß4) disease who presented at our center between 2005 and 2012. Our results showed that all patients had the Southeast Asian deletion (- -(SEA)) on one allele. The -α(3.7) (rightward) deletion was the most common on the other allele, followed by the -α(4.2) (leftward) deletion, Hb Constant Spring (Hb CS, α142, Term → Gln; HBA2: c.427T > C) and Hb Quong Sze [Hb QS, α125(H8)Leu → Pro; HBA2: c.377T > C] mutations. Two rare point mutations, α31(B12)Arg → Lys; HBA2: c.95G > A and Hb Zurich Albisrieden [α59(E8)Gly → Arg; HBA1: c.178G > C], were also identified. Four patients had a concomitant ß-thalassemia (ß-thal) heterozygosity. Our results reflect the genetic heterogeneity of Hb H disease and the interaction between Hb H disease and ß-thal trait in Southern China.

[Analysis of OCRL gene mutation in a male infant with Lowe syndrome].

OBJECTIVE: To identify pathological mutation in a Chinese male infant featuring oculocerebrorenal syndrome (also called Lowe syndrome). METHODS: Clinical data of the patient were collected. DNA was extracted from peripheral blood of the infant and his parents. All of the 24 exons and intron-exon splice sites of OCRL gene were amplified with PCR. Mutations were detected by direct sequencing the PCR products. RESULTS: The infant was found to have carried a c.1499G>A (p.R500Q) mutation in exon 15 of the OCRL gene, which was transmitted from his mother, who was heterozygous for the same mutation. The c.1499G>A mutation, discovered in Chinese population for the first time, has been reported to cause severe Lowe syndrome in other ethnic populations. CONCLUSION: The c.1499G>A mutation of the OCRL gene is probably responsible for the disease in the patient. Further study of this mutation may facilitate delineation of the genotype-phenotype correlation of this disease.

[Prenatal genetic diagnosis of oculocutaneous albinism type II through mutation detection combined with SNPs linkage analysis].

OBJECTIVE: To provide prenatal diagnosis for two families affected with oculocutaneous albinism (OCA), in both of which only 1 pathogenic allele has been identified. METHODS: To determine the clinical classification of OCA through DNA sequencing for TYR, P, TYRP1 and SLC45A2 genes in combination with phenotype analysis. Prenatal diagnosis was carried out by direct sequencing and intragenic SNPs family-based linkage analysis. RESULTS: In the first family, only 1 heterozygous mutation c.1255C>T was found in the proband, which was inherited from her mother. Together with its clinical phenotype, the proband was suspected to have OCA2 Screening of amniotic fluid, however, has found no mutation. With family-based linkage analysis, the fetus was deemed to be an OCA2 carrier. In the second family, again only one heterozygous mutation c.1920_1949 del30bp and ins AACA was found in the proband, which was inherited from her father. Together with its clinical phenotype, the proband was suspected to have OCA2. Screening of amniotic fluid has revealed a heterozygous mutation c.1920_1949 del30bp and ins AACA. By family-based linkage analysis, the fetus was deemed to be an OCA2 carrier. Both fetuses had a normal phenotype at birth. CONCLUSION: Prenatal genetic diagnosis has been provided for the first time for two families affected with OCA, in which only 1 pathogenic mutant allele was detected. The combined mutation detection and SNPs linkage analysis has turned out to be successful.

[A de novo mutation of P gene causes oculocutaneous albinism type 2 with prenatal diagnosis].

OBJECTIVE: To determine the genotype of a family affected with oculocutaneous albinism (OCA) and to provide genetic counseling and prenatal diagnosis. METHODS: To determine the genotypes and mutational sites through PCR and sequencing for all exons and exon-intron junctions of 4 OCA genes in the proband and the P gene of her parents. Prenatal genotyping of the fetus was carried out using amniocentesis sample. RESULTS: The patient was diagnosed with OCA2 based on a genotype of c.1327G>A/c.2360C>T. Her father was heterozygous for c.2360C> T, whilst her mother has none of the two mutations. c.1327G>A is therefore a maternal de novo mutation. Neither of the mutations was found in the fetus. CONCLUSION: A maternally inherited de novo mutation c.1327G>A has been identified in the patient. In order to detect de novo mutations, full sequence analysis is necessary.

Non-Targeted Metabolomic Study of Fetal Growth Restriction.

We aimed to explore the differential metabolites in amniotic fluid and its cells from fetuses with fetal growth restriction (FGR). A total of 28 specimens of amniotic fluid were collected, including 18 with FGR and 10 controls. Differential metabolites in all samples were detected by chromatography-mass spectrometry. Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to analyze the differences in metabolic spectra between the FGR and control groups through multidimensional and single-dimensional statistical analysis. The KEGG database was used for metabolic pathway enrichment analysis. Both PCA and OPLS-DA models showed a clear separation trend between FGR and control groups. We identified 27 differentially expressed metabolites in the amniotic fluid supernatant of the two groups (p < 0.05), of which 14 metabolites were up-regulated in the FGR group, and 13 metabolites, such as glutamate, phenylalanine, valine and leucine, were down-regulated. We also identified 20 differentially expressed metabolites in the amniotic fluid cell (p < 0.05), of which 9 metabolites, including malic acid, glycolic acid and D-glycerate, were up-regulated significantly and 11 metabolites, including glyceraldehyde, were down-regulated. Pathway analysis showed that most of the identified differential metabolites were involved in tricarboxylic acid cycle (TCA cycle), ABC transport, amino acid metabolism pathways and so on. The results indicated that many metabolic changes associated with FGR, which are mainly manifested by abnormal metabolism of amino acid in amniotic fluid and abnormal glucose metabolism including TCA cycle in amniotic fluid cells, respectively. Our findings provide more data for exploring the mechanism of FGR and the potential therapy targets.

Identification of novel variations of oculocutaneous albinism type 2 with Prader-Willi syndrome/Angelman syndrome in two Chinese families.

Objective: Oculocutaneous albinism (OCA) is an autosomal recessive disorder caused by a variety of genomic variations. Our aim is to identify the molecular basis of OCA in two families and lay the foundation for prenatal diagnosis. Methods: Four types of OCA-causing mutations in the TYR, p, TYRP1, or SLC45A2 genes were screened. Linkage analysis was performed because the mutations found in the p gene violated the laws of classical Mendelian heredity. Primer-walking sequencing combined with microsatellite and single-nucleotide polymorphism analysis was used to ascertain deletion ranges. Bioinformatics methods were used to assess the pathogenicity of the new mutations. Results: Proband 1 was diagnosed as OCA2 with Prader-Willi syndrome (PWS) due to a novel atypical paternal deletion (chromosome 15: 22330347-26089649) and a pathogenic mutation, c.1327G>A (Val443Ile), in the p gene of the maternal chromosome. The prenatal diagnosis results for family 1 indicated the fetus was a heterozygous carrier (c.1327G>A in the p gene) with a normal phenotype. Proband 2 was diagnosed as OCA2 with Angelman syndrome (AS) due to a typical maternal deletion of chromosome 15q11-q13 and a novel mutation, c.1514T>C (Phe505Ser), in the p gene of the paternal chromosome. This novel mutation c.1514T>C (Phe505Ser) in the p gene was predicted as a pathogenic mutation. Conclusion: Our study has shown clear genotype-phenotype correlations in patients affected by distinct deletions of the PWS or AS region and missense mutations in the p gene. Our results have enriched the mutation spectrum of albinism diseases and provided insights for more accurate diagnosis and genetic counseling.

Importance of fine particles in pesticide runoff from concrete surfaces and its prediction.

Pesticides such as pyrethroids have been frequently found in runoff water from urban areas and the offsite movement is a significant cause for aquatic toxicities in urban streams and estuaries. To better understand the origination of pesticide residues in urban runoff, we investigated the association of pyrethroid residues with loose particles in runoff water from concrete surfaces after treatment with commercial products of bifenthrin and permethrin. In runoff water generated from simulated precipitations after 1 to 89 d exposure under dry outdoor conditions, over 80% of the pesticides was found on particles >0.7 µm for most treatments. The solid-water partitioning coefficient (K(d)) on day 1 was estimated to be 2.4 × 10(3) to 1.1 × 10(5) L/kg for permethrin and bifenthrin on these solids. Except for solid formulations, the pesticide-laden particles likely originated from dust particles preexisting on the concrete before treatment and the disintegration of the surficial concrete matter through weathering. We consequently tested a simple sponge-wipe method to collect and analyze the loose particles on concrete. Concurrent analyses (n = 30) showed an excellent linear correlation between the amount of pesticides transferrable to runoff water and that on the wipe (R(2) = 0.78, slope = 1.13 ± 0.11, P < 0.0001). The fact that the linear relationship has a slope close to 1.0 suggests that this method may be used to predict pesticide residues available for contaminating runoff water before runoff actually occurs. The importance of loose particles should be considered when developing practices to mitigate pesticide runoff contamination from urban residential areas.

[Rapid prenatal genetic diagnosis of a fetus with a high risk for Morquio A syndrome].

OBJECTIVE: To provide rapid and accurate prenatal genetic diagnosis for a fetus with high risk of Morquio A syndrome. METHODS: Based on ascertained etiology of the proband and genotypes of the parents, particular mutations of the GALNS gene were screened at 10th gestational week with amplification refractory mutation system (ARMS), denaturing high performance liquid chromatography (DHPLC), and direct DNA sequencing. RESULTS: DHPLC screening has identified abnormal double peaks in the PCR products of exons 1 and 10, whilst only a single peak was detected in normal controls. Amplification of ARMS specific primers derived a specific product for the fetus's gene, whilst no similar product was detected in normal controls. Sequencing of PCR products confirmed that exons 1 and 10 of the GALNS gene from the fetus contained a heterozygous paternal c.106-111 del (p.L36-L37 del) deletion and a heterozygous maternal c.1097 T>C (p.L366P) missense mutation, which resulted in a compound heterozygote status. CONCLUSION: The fetus was diagnosed with Morquio A syndrome and a genotype similar to the proband. Termination of the pregnancy was recommended. Combined ARMS, DHPLC and DNA sequencing are effective for rapid and accurate prenatal diagnosis for fetus with a high risk for Morquio A syndrome. Such methods are particularly suitable for early diagnosis when pathogenesis is clear. Furthermore, combined ARMS and DHPLC are suitable for rapid processing of large numbers of samples for the identification of new mutations.

[Identification of a novel pathogenic mutation in MATP gene with oculocutaneous albinism type IV from a consanguineous marriage family].

OBJECTIVE: To clarify the pathogenicity-related genes and its mutations in an oculocutaneous albinism (OCA) patient from a consanguineous marriage family. METHODS: Polymerase chain reaction (PCR) and automatic DNA sequencing methods, chromosome walking by PCR amplification techniques (PCR-Walking), multiplex PCR in a single PCR tube with 3 primers bridging the breakpoint (Gap-PCR) and bioinformatic analysis were employed for screening the mutations and identifying the novel mutation in the patient and his family. RESULTS: A pathogenic deletion of 6365 bp was found in MATP gene with a range of c.562-1118 (± 2) to c.885 + 4923 (± 2). The patient was homozygous for deletion mutation. CONCLUSION: A large deletion mutation was first detected and identified in OCA4.

Multidimensional perspective of green financial innovation between green intellectual capital on sustainable business: the case of Pakistan.

This study investigates the multifaceted role of green innovation among green intellectual capitals (GICs) on business sustainability in Pakistan's manufacturing sector. A quantitative method based on the SEM model on SmartPLS and Stata analysis was used, which was supplemented by a survey of 800 Pakistani SME sector supply chain-associated participants. The findings revealed a significant effect of green intellectual capital and green innovation on business sustainability, while structural capital was found to have a significant moderating effect on the business sustainability of Pakistani firms. It has been determined that the relationship between GIC and BS has a strong moderation of green innovation. Furthermore, the relationship and impact of GICs on the business sustainability of Pakistani manufacturing companies were statistically significant, and green innovation played a moderating role between GIC and business sustainability. Therefore, it has been suggested that Pakistani manufacturing companies participate in eco-innovation to progress business sustainability.

Sorption and desorption of pyrethroid insecticide permethrin on concrete.

Use of pesticides around residential homes is linked to contamination of urban waterways, where impervious surfaces like concrete are considered as sources or facilitators of the contamination. However, the fate of pesticides on urban hard surfaces is poorly understood. We characterized sorption and desorption of permethrin, the most used pyrethroid insecticide, on concrete surfaces, to understand its availability for contaminating runoff water. Sorption of (14)C-permethrin to concrete was rapid, and the sorption isotherm was linear, with surface area-normalized K(d) of 1.91 ± 0.1 mL/cm(2). When small permethrin-treated concrete cubes (14 × 14 × 8 mm) were subjected to 300 h sequential desorption, both the parent compound and total (14)C showed an initial rapid desorption, followed by prolonged slow desorption. Meanwhile, permethrin became more resistant to desorption as the pesticide contact time on the concrete increased. When desorption was performed 1 and 7 d after the treatment, the desorbed permethrin after 300 h was 34.1 ± 3.2% and 23.7 ± 1.1% of the spiked amount, respectively, as compared to 56.2 ± 6.1% for the freshly spiked samples. The decreased desorption was partially attributed to permethrin decomposition on the alkaline concrete. However, even after 300 h, over 20% of the applied (14)C still remained in the concrete. Therefore, when pesticide-treated concrete surfaces come in contact with runoff water, elevated concentrations may be expected initially, while the extended desorption implies a potential for sustained contamination.

[Prenatal diagnosis of oculocutaneous albinism type IV and discovery of a novel mutation].

OBJECTIVE: To provide guidance for clinical genetic counseling and prenatal diagnosis of oculocutaneous albinism (OCA) in China. METHODS: PCR and automatic DNA sequencing were applied to obtain the genotypes of the patients and their parents in three Chinese albinism families. Prenatal gene diagnoses were performed at early pregnancy by chorionic villus sampling (CVS) or by amniocentesis at mid-pregnancy. RESULTS: The three patients were all OCA4, whose genotypes were G349R/c.870delC, G349R/P419L and G349R/D160H, respectively. The three couples had been diagnosed as carriers. In family 1, the first fetus was diagnosed as affected. Termination of pregnancy was opted following genetic counseling. The second fetus (monozygotic twin) was heterozygous only with the paternal G349R mutation. The fetus in family 2 did not get either one of the two mutations. The fetus in family 3 was heterozygous only with the paternal G349R mutation. CONCLUSION: This study detected three reported pathogenic mutations of the membrane associated transporter protein gene (MATP), including G349R, D160H and P419L, and identified a novel pathogenic mutation c.870delC. The prenatal gene diagnosis of OCA4 will be important to prevent the birth of affected child.

Identification of a novel SUOX pathogenic variants as the cause of isolated sulfite oxidase deficiency in a Chinese pedigree.

BACKGROUND: Isolated sulfite oxidase deficiency (ISOD) is a life-threatening rare autosomal recessive disorder caused by pathogenic variants in SUOX (OMIM 606887) gene. The aim of our study was to establish a comprehensive genetic diagnosis strategy for the pathogenicity analysis of the SUOX gene within a limited time and to lay the foundation for precise genetic counseling, prenatal diagnosis, and preimplantation genetic diagnosis. METHODS: Two offspring from one set of parents were studied. Next-generation sequencing (NGS) was used to screen for disease-causing gene variants in a family with ISOD. Then, Sanger sequencing was performed to verify the presence of candidate variants. Sulfite, homocysteine and uric acid levels were detected in the patients. According to the ACMG/AMP guidelines, the pathogenicity level of novel variants was annotated. RESULTS: The nonsense pathogenic variant (c.1200C > G (p.Y400*)) and a duplication (c.1549_1574dup (p.I525 Mfs*102)) were found in the SUOX gene in the proband. The nonsense mutation (c.1200C > G (p.Y400*), pathogenic, isolated sulfite oxidase deficiency, autosomal recessive) has been reported as pathogenic and the duplication (c.1549_1574dup (p.I525 Mfs*102), pathogenic, isolated sulfite oxidase deficiency, autosomal recessive) was novel, which was classified as pathogenic according to the ACMG/AMP Standards and Guidelines. CONCLUSION: We established the pathogenicity assessment in ISOD patients based on ACMG/AMP Standards and Guidelines and this is the first ISOD patient reported in mainland China. We also discovered that ISOD is caused by SUOX gene duplication mutation, which enriches the spectrum of SUOX pathogenic variants.